Working features:
1) Push button kill switch
2) Control knob is now the "Throttle pedal" controls speed of acceleration to top speed
3) The other control knob is for overall gain
4) ti slightly increased over previous versions for tighter feel, less tip to make it move along
5) Softstart working.
6) Comes on when perfectly level now.
7) Designed for the low ground clearance mechanical design
8) manual tilt lever is working

Wires to hand controller:
+5V Red
A2 grey wire OverallGain control via CUT OUT SWITCH
A3 orange wire Tilt lever back
A4 green wire Throttle control knob
A5 blue wire Tilt lever forwards

#include <avr/io.h>
#include <avr/pgmspace.h>
#include <avr/interrupt.h>
#include <math.h>

  /*I turn port B2 on and off once per main program cycle so I can attach an oscilloscope to it and work out the program cycle time
    I use the cycle time to work out gyro angle change per cycle where you have to know the length of this time interval*/
   PORTB &= (0<<PB2);

  /*ti represents scaling for the "i" or integral factor (currently 2.2 here)
    gyroangledt is anglechange since last CYCLE in degrees from gyro sensor, where ti is scaling factor (should in theory be about 1 but 2.2 makes board feel tighter)
 
    ganglerate is now in units of degrees per second
    aa varies the time constant, i.e smaller aa value makes accelerometer time constant longer as it slowly corrects for the gyro drift*/

   aa=0.005;
  
   gyroangledt = (float)ti*cycle_time*gangleratedeg;
   gangleraterads=(float)gangleratedeg*0.017453;
  

cur_speed = (float)(cur_speed + (Throttle_pedal * balance_torque * cycle_time)) * 0.999;

}

  TCCR0 = 0 |
    (1<<CS02) | (1<<CS01) | (1<<CS00); // External clock to Pin T0 Clock on rising edge/1024

  // PWM mode is "PWM, Phase Correct, 10-bit"
  TCCR1A = 0 |
    (1<<COM1A1) | (1<<COM1A0) | // set on match up, clear on match down
    (1<<COM1B1) | (1<<COM1B0) | // set on match up, clear on match down

    (1<<WGM11) | (1<<WGM10); //OCR1_Max is 1023 so these are set like this

  TCCR1B = 0 |
    (1<<CS10); // prescaler divide by 1 see P131 datasheet about prescaling values to change here.
  /* 16 MHz / 1 / 1024 / 2 gives 8 kHz, probably about right */
}

void set_motor()
/* The leveli terms is the level term rescaled from -1023 to +1023 as an integer ready to send to the PWM motor control ports that are in turn connected to the OSMC*/
{

  //if (level<-0.9) level= -0.9;//checks we are within sensible limits
  //if (level>0.9) level=0.9;

  int16_t leveli = (int16_t)(level*1023); //NOTE here we take the floating point value we have ended up with for "level", we multiply it by 1023 and then make it into an integer before feeding the value into the PWM generator as "leveli"

  if (leveli<-1020) leveli=-1020;//double-checks we are within sensible PWM limits as do not want to suddenly be thrown off the board
  if (leveli>1020) leveli=1020;
 

/*Set up LED or buzzer on Port B1 to warn me to slow down if torque to be delivered is more than 50% of max possible
  The reason for this is that you always need some reserve motor power in case you start tipping forward at speed
  If motor already running flat-out you would be about to fall over at high speed!
  Some use an auto-tip back routine to automatically limit top speed. For now I will do it this way as easier*/

  if (level<-0.7 || level>0.7) {
   PORTB |= (1<<PB1);
    }
  else {
   PORTB &= (0<<PB1);
    }

  softstart = (float) softstart+0.001;
  if (softstart>1.0) softstart=1.0;

 
  //PORTC |= (0<<PC1);     // AHI=1  PinC3, BHI=1 PinC2 set both to ON for OSMC to work and both to OFF to shut motor down
/*NOTE: Not sure why but to stop motor cutting out on direction changes I had in the end to hard wire AHI and BHI to +12V */
/* Un-disabled OSMC by setting PinC1 output to zero, a 1 would disable the OSMC*/
  PORTC |= 0x0c; //make C1 pulled down so un-disables the OSMC i.e. enables it.
  PORTC &= ~0x02; //disable is off
  if (leveli<0) {
   
    OCR1A = -leveli;   // ALI is PWM   going backwards as leveli variable is a negative signed value, keep the minus sign in here!
    OCR1B = 0;         // BLI = 0
  }
  else {
    OCR1A = 0;         // ALI = 0      going forwards as leveli variable is a positive signed value
    OCR1B = leveli;    // BLI is PWM
  }
 
}

int main(void)
{
 
    InitPorts();

 adc_init();

 timer_init();

/*  Initial tilt-start code
 Turn on micro while board tipped to one side,
 rider about to step onto it, if tilt angle crosses zero (mid) point balance algorithm
 becomes operational otherwise locked in this loop forever until it is tipped to level position as rider
 gets onto board*/
    tipstart=0;
 accelraw = 0;

    while (tipstart<1){

                          }

 if (accsum<504 || accsum>524) {
 //   if (x_accdeg>0) {
          tipstart=0;
     }
    else {
          tipstart=1;
             softstart=0.4;
     }
    }

    angle=0;
    cur_speed=0;
/* end of tilt start code. If go beyond this point then machine has become level and is active*/

    sei();

 
 while (1) {
 
 sample_inputs();

 set_motor();